Bearing assemblies are typically circular in shape, and generally comprise rolling elements disposed between raceways in bearing rings. Rolling elements take many forms, including spherical balls, rollers or various other configurations, such as cone-shaped tapered rollers or barrel-shaped spherical rollers.
Bearings are widely used in wind power generation, particularly in the nacelle of the turbine, to support components in the gearbox and the main shaft of the wind turbine, which, typically the blade rotor assembly is mounted on. In large size wind turbines, the nacelle can be dozens of feet above the ground, thus maintaining the bearings supporting the main shaft of the blade rotor assembly can involve substantial labor, costs and often the use of specialized equipment, such as large cranes.
Both radial and thrust loads are generated during power generation cycles in a wind turbine as a result of the action of the wind on the blade rotors and, in turn, the main shaft. The main shaft bearing must, therefore, be able to support both radial and axial (or thrust) loads.
Various bearing assemblies are disclosed for rotatably supporting the main shaft of the wind turbine, for example, U.S. Pat. No. 7,918,649 discloses a double row spherical roller assembly with one row having rollers of different lengths from every roller of the other row.